org.apache.hadoop.hbase.coprocessor

Interface EndpointObserver

All Known Implementing Classes:

AccessController

@InterfaceAudience.LimitedPrivate(value="Coprocesssor")
 @InterfaceStability.Evolving
public interface EndpointObserver

Coprocessors implement this interface to observe and mediate endpoint invocations on a region.

Exception Handling

For all functions, exception handling is done as follows:

• Exceptions of type IOException are reported back to client.
• For any other kind of exception:
  • If the configuration CoprocessorHost.ABORT_ON_ERROR_KEY is set to true, then the server aborts.
  • Otherwise, coprocessor is removed from the server and DoNotRetryIOException is returned to the client.

Method Summary

Modifier and Type	Method and Description
default void	postEndpointInvocation(ObserverContext<RegionCoprocessorEnvironment> ctx, com.google.protobuf.Service service, String methodName, com.google.protobuf.Message request, com.google.protobuf.Message.Builder responseBuilder) Called after an Endpoint service method is invoked.
default com.google.protobuf.Message	preEndpointInvocation(ObserverContext<RegionCoprocessorEnvironment> ctx, com.google.protobuf.Service service, String methodName, com.google.protobuf.Message request) Called before an Endpoint service method is invoked.

Method Detail

preEndpointInvocation

default com.google.protobuf.Message preEndpointInvocation(ObserverContext<RegionCoprocessorEnvironment> ctx,
                                                          com.google.protobuf.Service service,
                                                          String methodName,
                                                          com.google.protobuf.Message request)
                                                   throws IOException

Called before an Endpoint service method is invoked. The request message can be altered by returning a new instance. Throwing an exception will abort the invocation. Calling ObserverContext.bypass() has no effect in this hook.

Parameters:

ctx - the environment provided by the region server

service - the endpoint service

request - Request message expected by given Service's method (by the name methodName).

methodName - the invoked service method

Returns:

the possibly modified message

Throws:

IOException

postEndpointInvocation

default void postEndpointInvocation(ObserverContext<RegionCoprocessorEnvironment> ctx,
                                    com.google.protobuf.Service service,
                                    String methodName,
                                    com.google.protobuf.Message request,
                                    com.google.protobuf.Message.Builder responseBuilder)
                             throws IOException

Called after an Endpoint service method is invoked. The response message can be altered using the builder.

Parameters:

ctx - the environment provided by the region server

service - the endpoint service

methodName - the invoked service method

request - Request message expected by given Service's method (by the name methodName).

responseBuilder - Builder for final response to the client, with original response from Service's method merged into it.

Throws:

IOException